Method and apparatus for verifying a video format supported by a display device

ABSTRACT

A method ( 200 ) for verifying a video format supported by a display device ( 25 ). The display device ( 25 ) is adapted to receive a television signal from a video source ( 10 ) via a video interface ( 15 ). The method includes: receiving ( 202 ) a data structure ( 75 ) provided by the display device ( 25 ), the data structure ( 75 ) specifying a plurality of timing parameters associated with a supported video format; providing ( 204 ) a plurality of predetermined value ranges, each of the plurality of predetermined value ranges corresponding to one of the plurality of timing parameters; separating ( 206 ) the data structure into a plurality of portions, each of the plurality of portions corresponding to one of the plurality of timing parameters; comparing ( 208 ) at least some of the plurality of portions with at least some of the plurality of predetermined value ranges; and based on the comparisons, determining whether the supported video format is verified.

FIELD OF THE INVENTION

Aspects of this invention relate generally to video signal processing,and, more particularly, to a method and apparatus for verifying a videoformat supported by a display device.

BACKGROUND OF THE INVENTION

Program providers such as television networks or stations, studios,Internet broadcasters or service providers, cable operators, satelliteoperators and the like, deliver video programming to consumers viadigital signals. Devices and signals involved in the delivery of digitalvideo programming to consumers may comply with various industryspecifications, or standards, which have been promulgated by groupsdesiring, among other things, to ensure interoperability between systemsand devices that deliver the digital video programming.

The Digital Display Working Group (“DDWG”), for example, has published adocument entitled Digital Visual Interface, Revision 1.0 (hereinafterreferred to as the “DDWG Specification”), which sets forth an industrystandard for a physical digital visual interface (“DVT”), and a protocolfor electrical signaling thereon, between a personal computing deviceand a display device. The DDWG Specification is hereby incorporated byreference in its entirety for all purposes, as if set forth in fullherein. Likewise, the Electronic Industries Alliance (“EIA”) and theConsumer Electronics Association (“CEA”) have together promulgated astandard entitled “EIA/CEA-861,” published in January, 2001 (hereinafterreferred to as the “EIA/CEA-861 Standard”), which defines video timingrequirements, discovery structures, and data transfer structures usedfor implementing digital interfaces on digital televisions or monitors.The EIA/CEA-861 Standard is also hereby incorporated by reference in itsentirety for all purposes, as if set forth in full herein.

Both the DDWG Specification and the EIA/CEA-861 Standard addressmandatory uses of a data structure known as the Video ElectronicsStandards Association's (“VESA”) Extended Display Identification Data(“EDID”) data structure (hereinafter referred to as the “EDID DataStructure,” which is described in detail in a document published by VESAentitled “EDID Standard, Version 3, November, 1997, incorporated byreference in its entirety for all purposes, as if set forth in fullherein). The EDID Data Structure is stored by display devices such asdigital television displays and monitors, and defines, among otherthings, data formats and timings used to carry information, such asvideo programming, from source devices, such as cable or terrestrialset-top boxes, digital video cassette recorders (“VCRs”), computers, anddigital video disk (“DVD”) players, to the display devices, and furtherdefines the display devices' capabilities to receive and render data insuch data formats/timings.

Among other things, the DDWG Specification and the EIA/CEA-861 Standardrequire that source devices read the EDID Data Structure from displaydevices (the EDID Data Structure may be transmitted from display devicesto source devices over physical links such as I²C buses, for example),to determine data format/timing capabilities supported by the displaydevices. Neither the DDWG Specification nor the EIA/CEA-861 Standard,however, currently mandates how source devices use information from theEDID Data Structure to select data formats/timings for sending videoprogramming to display devices.

Customer dissatisfaction with the performance of either source devicesor display devices is a danger when display devices present inaccurateEDID Data Structures—for example, the use of information obtained fromreading inaccurate EDID Data Structures may result in the source devicessending video using data formats/timings not supported by, or optimalfor, the display devices.

There is, therefore, a need for a method and apparatus for verifying avideo format supported by a display device, which is able to provide arobust consumer experience even in the instance where the display deviceprovides an inaccurate EDID Data Structure.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, a method forverifying a video format supported by a display device is provided. Thedisplay device is adapted to receive a digital television signal from adigital video source via a digital video interface. The method includes:receiving a data structure provided by the display device, the datastructure specifying a plurality of timing parameters associated with asupported video format; providing a plurality of predetermined valueranges, each of the plurality of predetermined value rangescorresponding to one of the plurality of timing parameters; separatingthe received data structure into a plurality of portions, each of theplurality of portions corresponding to one of the plurality of timingparameters; comparing at least some of the plurality of portions with atleast some of the plurality of predetermined value ranges; and based onthe comparisons, determining whether the supported video format isverified.

In accordance with another aspect of the present invention, acomputer-readable medium is encoded with a computer program which, whenexecuted, implements the foregoing method. The method may furtherinclude including the supported video format in a schedule of supportedvideo formats associated with the display device, based on whether thesupported video format is verified—if the supported video format is notverified, the supported video format is not included on the schedule; ifit is verified, it is included on the schedule. A picture aspect ratioof the verified, supported video format may also be determined. A userof the display device may select a preferred video format, from a menu,and based on the user's selection, the digital video interface transmitsthe digital television signal to the display device in the selectedformat.

In accordance with a further aspect of the present invention, anapparatus for verifying a video format supported by a display deviceincludes a computer-readable storage medium, and a processor responsiveto the computer-readable storage medium and to a software program. Thesoftware program, when loaded into the processor, is operative toperform a method including: receiving a data structure specifying aplurality of timing parameters associated with a supported video formatof the display device; accessing a plurality of predetermined valueranges, each of the plurality of predetermined value rangescorresponding to one of the plurality of timing parameters; separatingthe received data structure into a plurality of portions, each of theplurality of portions corresponding to one of the plurality of timingparameters; comparing at least some of the plurality of portions with atleast some of the plurality of predetermined value ranges; and based onthe comparisons, determining whether the supported video format isverified. The processor may be associated with the display device, aset-top box adapted to transmit a video signal to the display device, ora digital video interface responsive to the display device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a video signal handling system, inaccordance with various aspects of the present invention.

FIG. 2 is a flowchart of a method for verifying a video format supportedby a display device, in accordance with an aspect of the presentinvention.

FIG. 3 is a flowchart of a process for identifying a particular videoformat associated with a timing parameter, provided by a display device,representing the number of horizontal active pixels per line.

FIG. 4 is a flowchart of a process for identifying a particular videoformat associated with a timing parameter, provided by a display device,representing the number of horizontal blanking pixels per line.

FIG. 5 is a flowchart of a process for identifying a particular videoformat associated with a timing parameter, provided by a display device,representing the number of vertical active lines.

FIG. 6 is a flowchart of a process for identifying a particular videoformat associated with a timing parameter, provided by a display device,representing the number of vertical blanking lines.

FIG. 7 is a flowchart of a process for identifying a particular videoformat associated with a timing parameter, provided by a display device,representing the horizontal synchronization timing offset.

FIG. 8 is a flowchart of a process for identifying a particular videoformat associated with a timing parameter, provided by a display device,representing the horizontal synchronization pulse width.

FIG. 9 is a flowchart of a process for identifying a particular videoformat associated with a timing parameter, provided by a display device,representing the vertical synchronization timing offset.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to the drawings, where like numerals designate likecomponents, FIG. 1 is a block diagram of a video signal handling system10 (“system 10”), which serves as a digital video source for thedelivery of a digital video signal 13 to a display device 25, over adigital interface 15.

System 10 receives video signal 12 from video source 11. As shown,system 10 is a cable set-top box (for example, Motorola's DCT-5100™set-top box), video source 11 is a hybrid fiber-optic/coax cable networkoperated by a cable television operator, video signal 12 is a digitalprogramming source supplied by the cable operator, video signal 13 is adigital video signal (e.g. component RGB (Red-Green-Blue) representationof the original signal), digital interface 15 is a Digital VisualInterface (“DVI”) defined by the DDWG Specification, and display device25 is a digital television monitor.

System 10, however, may be any device or combination of devices capableof receiving and/or rendering video signal 12 to display device 25,including but not limited to a digital video cassette recorder (“VCR”),a digital video disk (“DVD”) player, a computer, or any other consumerappliance responsive to a digital video interface transmitter device;video source 11 may be any public or private, wired or wireless, videotransmission infrastructure or technology, including but not limited toa fiber-optic network, a coaxial cable network, a hybrid network, asatellite network, cellular network, the Internet, a television network,a radio network, a copper wire network, or any other existing or futuretransmission infrastructure or technology, operated by any type ofprogram provider, such as a television network or station, a studio, anInternet broadcaster or service provider, a cable operator, or asatellite operator; video signal 12 may be any pre-recorded or liveanalog or digital electronic signal representing an image and/or audio,in any format; video signal 13 may be a digital video signal destinedfor any type of display device; digital interface 15 may be any wired orwireless digital visual interface that transmits the EDID DataStructure, and display device 25 may be any digital display device,including but not limited to a computer screen, such as a CRT, a liquidcrystal display, or a plasma display.

System 10 includes external network connection/communication interfaces59, which support devices such as modems, streaming media players andother network connection support devices and/or software, coupledthrough local or wide area networks (not shown) to program providers andproviders of other content.

System 10 further includes an in-band tuner 43, which tunes to a channelsignal selected by a consumer (not shown) via user interface 55. Userinterface 55 is also used to provide requested inputs to system 10, suchas display format preferences (discussed further below) for displaydevice 25. User interface 55 may be any type of known or future deviceor technology allowing the consumer to select video formats, channels orprograms the consumer wishes to receive, such as a remote control,mouse, microphone, keyboard, or display.

NTSC Demodulator 40 and QAM Demodulator 42 are responsive to in-bandtuner 43. QAM Demodulator 42 may be any type of digital demodulatordevice that may include but is not limited to ATSC demodulation. NTSCDemodulator 40 includes components responsive to receive analog versionsof a channel signal. QAM Demodulator 42 includes components responsiveto receive digital versions of a channel signal. A QAM demodulator 42component receives digital data packets from one or more digitalsources, such as a digital television signal, a Moving Pictures Experts'Group (MPEG) transport stream, or a media stream from an externalnetwork connection 59, such as a cable modem, using well-known methodsand techniques. An analog demodulator component 40 receives an analogversion of a channel signal, and decodes signals and markers accordingto well-known methods and techniques. Demodulator 40 is operative tooutput video information 17, which includes video or audio data arrangedfor formatting in accordance with a predetermined media format.

Video decoder 44 is responsive to video information 17. Video decoder 44is operative for decoding video information 17 and converting it into adigital representation of the received video information, which isoutput as digital video information 18 and 19.

Digital video information 18 and 19 are preferably arranged inaccordance with Consultative Committee International Radio (CCIR) 656,which is video transmission standard well-known to those familiar withthe art. Video information 18 that may require format translation ormodification for compatibility with capabilities of the storage medium64 may be passed to encoder 41 for formatting. Video information 19 thatis in a format preferred for use by the Multi Media Processor 49 may bepassed directly to the Multi Media Processor 49.

Multi-Media Processor 49 is operative to perform predetermined codingtechniques to arrange video information 19 and video information 20 intoformats displayable by display device 25. Analog video programs arepreferably passed to the Multi Media Processor 49 via video information19 and digital video programs are preferably passed to the Multi MediaProcessor 49 via video information 20, which originated from the QAMdemodulator 42. Video information that is retrieved and played back fromthe Storage Medium 64 is passed to the Multi Media Processor 49 viavideo information 20.

Encoder 41 is operative to perform predetermined coding techniques toproduce encoded video signal 20 for transmission thereto, or for storagein storage medium 64.

Storage medium 64 is responsive to receive, among other things, encodedvideo signal 20 for storage, and to receive and store an EDID DataStructure 75 (discussed further below) from display device 25. Storagemedium 64 may be any local or remote device, now known or laterdeveloped, capable of recording data, including but not limited to ahard disk drive, a videocassette recorder tape, all types of compactdisks and digital videodisks, a magnetic tape, a home router, or aserver.

MPEG Decoder/Multi-Media Processor 49 is responsive to receive anddecode video signal 19 and video signal 20, format received video intoits Red-Green-Blue (RGB) components and to transmit to display device25, via Digital Visual Interface transmitter 50, in response toinstructions from user interface 55. Internal arrangements of decoder 49are well known—decoder 49 may include analog-to-digital converters, oneor more storage media and/or buffers, and general or special-purposeprocessors or application-specific integrated circuits, along withdemultiplexors for demultiplexing and/or synchronizing at least twotransport streams, for example, video and audio. Video and audiodecoders and/or analog and digital decoders may be separate, withcommunication between separate decoders allowing for synchronization,error correction and control.

Digital Visual Interface (“DVT”) transmitter 50 has a physical andlogical architecture as set forth in the DDWG Specification, and may bepart of, or separate from, system 10. DVI transmitter may also beincorporated into the MPEG Decoder/Multi Media Processor 49. Inoperation, DVI transmitter 50 is responsive, via I²C bus 60, to accessfunctions of system 10, such as storage medium 64, processor 39(discussed further below) and software 22 (also discussed furtherbelow), and is responsive to display device 25 via digital interface 15.Among other things, DVI transmitter 50 arranges for the receipt of EDIDData Structure 75 from display device 25 via I²C bus 72 and digitalinterface 15, and, based on verification of video formats supported bydisplay device 25 in accordance with aspects of the present invention(discussed further below), coordinates transmission of digital signal 13over DVI interface 15, in a format compatible with video formatssupported and displayable by display device 25.

Display device 25, which may also include speakers for outputting audiosignals, displays digital video programming received from system 10 viadigital video signal 13 over digital interface 15. Display device 25 maysupport one or more digital television formats set forth in theEIA/CEA-861-B Standard, for countries using 60 Hz systems, including twoHDTV formats (1920×1080i and 1280×720p), one EDTV format (720×480p), andone standard definition format (720×480i). Picture aspect ratios of 16:9and 4:3 are also specified. It will be appreciated that otherspecifications or standards may specify different or additional waveformtiming parameters/formats, and the digital television formatsparameters/formats referred to herein are set forth for purposes ofexample, and not limitation.

Functional arrangements of certain components of display device 25 aredepicted—DVI transmitter 71, I²C bus 60, storage medium 70, and videoengine 77—that pertain to the delivery of EDID Data Structure 75 to DVItransmitter 50, and ultimately to other functional elements of system10, such as storage medium 64 and processor 39, via I²C bus 72 and I²Cbus 60. DVI receiver 71 has a physical and logical architecture as setforth in the DDWG Specification, and is responsive to DVI transmitter 50over digital interface 15, to storage medium 70 via I²C bus 72, and tovideo engine 77, which represents a processor, computer programs and/orphysical components operative to implement the functions of displaydevice 25 relating to display of pictures based on RGB video signal 13.

As mandated by the DDWG Specification or the EIA/CEA-861 Standard, orother specifications or standards, if applicable, in response to arequest from system 10, display device 25 transmits EDID Data Structure75 to system 10. EDID Data Structure 75 may be transmitted via I²C bus72 and/or I²C bus 60, for storage by storage medium 64. The request mayresult from an event such as hot-plug connection/detection of displaydevice 25 and system 10 (a feature set forth in the DDWG Specification),or in response to another suitable predetermined trigger, such as anevent or a message.

In principle, the transmitted EDID Data Structure must set forth, amongother things, waveform timing parameters for each video format supportedby display device 25 that may be used to carry video signal 13 fromsystem 10. The waveform timing parameters are to be provided in 18-bytedetailed timing descriptors in predetermined portions of the EDID DataStructure. Each timing parameter is generally one predetermined block ofbytes of the EDID Data Structure, and expressed in hexadecimal format.Examples of timing parameters for particular formats include, but arenot limited to: the number of horizontal active pixels per line; thenumber of horizontal blanking pixels per line; the number of verticalactive lines; the number of vertical blanking lines; the horizontalsynchronization timing offset; the horizontal synchronization pulsewidth; the vertical synchronization timing offset; the horizontal imagesize; and the vertical image size.

Processor 39 and software 22 are illustrated functionally, and areresponsive to various elements of system 10, including demodulator 40and 42, encoder 41, storage medium 64, decoder 49, and DVI transmitter50. When loaded into a processor, such as processor 39, software 22 isoperative to control verification of video formats and timings supportedby display device 25, by accessing and analyzing EDID Data Structure 75in accordance with aspects of the present invention (discussed furtherbelow). It will be appreciated, however, that aspects of the presentinvention are not limited to any specific embodiments of computersoftware or signal processing methods. For example, one or moreprocessors packaged together or with other elements of system 10 mayimplement functions of processor 39 in a variety of ways. It will alsobe appreciated that software 22 may be any stored instructions, in oneor more parts (stored, for example, on storage medium 64, or anotherinternal or external storage medium such as a read-only-memory or arandom-access memory) electronically controlling functions provided bysystem 10, including firmware, and may be used or implemented by one ormore elements, including one or more processors, of system 10.

During normal operation of system 10, a consumer using user interface 55selects digital video programming for viewing on display device 25. FIG.2 is a flowchart of a method for verifying one or more video formatssupported by a display device, such as display device 25, which isadapted to receive digital television signals, such as digital videosignals 13, from a digital video source, such as source 11, via adigital video interface, such as digital interface 15, in accordancewith aspects of the present invention. Examples of digital televisionformats that may be supported by display device 25 include two HDTVformats (1920×1080i and 1280×720p), one EDTV format (720×480p), and onestandard definition format (720×480i). One or more supported pictureaspect ratios of 16:9 and 4:3 are also possible.

The method begins at block 200, and continues at block 202, where a datastructure, such as EDID Data Structure 75, is received. The datastructure is provided by the display device, and specifies timingparameters associated with the one or more video formats supported bythe display device. When display device 25 is initially coupled tosystem 10 via digital interface 15, EDID Data Structure 75 may beautomatically sent to system 10—a system-level function such as hot-plugdetection, for example, may be used to trigger automatic transmission ofEDID Data Structure 75 from display device 25 to system 10. The datastructure may be stored in a memory, such as storage medium 64.

Examples of timing parameters for a particular format include, but arenot limited to: the number of horizontal active pixels per line (“HAP”);the number of horizontal blanking pixels per line (“HBP”); the number ofvertical active lines (“VAL”); the number of vertical blanking lines(“VBL”); the horizontal synchronization timing offset (“H-SYNC”); thehorizontal synchronization pulse width (“H-PULSE”); the verticalsynchronization timing offset (“V-SYNC”); the horizontal image size(“H-SIZE”); and the vertical image size (“V-SIZE”). In addition, one ormore aspect ratios (“AR”) of 16:9 and 4:3 are possible for certainformats. Each timing parameter may be expressed in the data structure asone byte in hexadecimal format. At block 204, a plurality ofpredetermined value ranges, each value range corresponding to aparticular timing parameter of a particular format, is provided. Thevalue ranges may be stored, for example, in a memory, such as storagemedium 64. The predetermined value ranges may represent, for example,typical ranges of decimal representations of the lower eight bits ofparticular timing parameter values that would be expected values for agiven video format. Such typical, or expected, ranges may be obtained byobserving actual transmitted timing values for different formats, orestablished in another suitable manner, such as approximation based onexpected values and minimum/maximum differences between correspondingtiming formats. Table 1 provides examples of predetermined value rangescorresponding to exemplary formats and timing parameters.

TABLE 1 Predetermined Value Ranges 1920 × 1080i 1280 × 720p 720 × 480p720 × 480i HAP 1900–1940 1280–1300 700–740 1420–1460 HBP 260–300 350–390118–158 256–296 VAL 520–550 700–740 460–500 220–260 VBL (same as 27–3342–48 (same as 720 × 480i 720 × 480i format; not format; not determi-determinative) native) H-SYNC 80–96 102–118  8–24 30–46 H-PULSE 42–4638–42 60–64 122–126 V-SYNC H-SIZE/ N/A N/A 1.33 +/− 0.20 1.33 +/− 0.20V-SIZE, 4:3 AR H-SIZE/ Assume 16:9 Assume 16:9 1.77 +/− 0.20 1.77 +/−0.20 V-SIZE, 16:9 AR

The received data structure is separated, at block 206, into a number ofportions. Each of the portions corresponds to a timing parameter for aparticular format. The portions may be, for example, timing parametersset forth in 18-byte detailed timing descriptors in predeterminedportions of the EDID Data Structure.

At block 208, at least some of the portions are compared with at leastsome of the predetermined value ranges, and it is verified, based on thecomparisons, whether the display device supports one or more videoformats. FIGS. 3–9 are flowcharts illustrating an exemplary process forverifying whether a display device supports the video formats set forthin Table 1, using, for comparisons, the timing parameters (parsed fromEDID Data Structure 75) of HAP (shown in FIG. 2), HBP (shown in FIG. 3),VAL (shown in FIG. 4), VBL (shown in FIG. 5), H-SYNC (shown in FIG. 6),H-PULSE (shown in FIG. 7), V-SYNC (shown in FIG. 9), and Aspect Ratio(which is calculated as the ratio of H-SIZE-to-V-SIZE, and correspondingvalue ranges for the lower eight bits of the applicable timingparameters. For each timing format set forth in EDID Data Structure 75,the selected timing parameters are compared to the predetermined valueranges.

If, after reading and processing EDID Data Structure 75 as shown in theexamples of FIGS. 3–9, the EDID Data Structure indicates one or moreverifiable supported video formats, then the verified video formats maybe included on a schedule, such as a format menu, that allows the user,via user interface 55, to manually select the video format that heprefers to use with display device 25. Based on the user's selection ofa preferred video format from the format menu, system 10 ensures thatdigital video signal 13 is encoded in the selected video format viawell-known methods and techniques, and transmits digital video signal 13to display device 25 via digital interface 15.

If, after reading and processing EDID Data Structure 75 as shown in theexamples of FIGS. 3–9, it is determined that values for one or moretiming parameters within a particular video format are not within theexpected predetermined value ranges, then it may be inferred that theEDID Data Structure contained incorrect information, or the particularvideo format is not supported by the display device. If it is determinedthat a particular format listed in the EDID Data Structure is not infact supported by the display device, or if no identifiable formats arelisted in the EDID Data Structure (for example, the entire EDID DataStructure was bad—contained corrupt or fictitious information orcontained no video formats/timing parameters), then system 10 may allowthe user to select any video format supported by system 10, via a formatmenu accessed using user interface 55.

If it is determined that EDID Data Structure 75 contains incorrecttiming parameter information, but that a particular format is in factsupported by the display device (for example, if a predetermined numberof, or particular ones of, timing parameters do not fall within expectedvalue ranges, while another predetermined number of, or particular onesof, timing parameters do fall within the expected value ranges), thensystem 10 may obtain correct timing parameters for a particular videoformat from another source, and may include the video format on the menupresented to the user, or may reject the incorrect formats, and defaultto the base format of 720×480p, at an aspect ratio of 4:3, then allowthe user to select his desired format from a GUI.

When obtaining correct timing parameters, system 10 may retrieve locallystored timing parameters, from storage medium 64, for example, or mayretrieve remotely stored timing parameters—from, for example, one ormore locations, such as directories, servers, or dedicated communicationchannels or data carousels. To retrieve remotely stored timingparameters, system 10 may be configured to search or consult apredetermined list of directories, channels or servers for the existenceof correct timing parameters, or correct timing parameters may be“pushed” to system 10 by a remote operator, such as a cable operator.Remote locations or downloads may be accessed or accomplished viaexternal network connection/communication interfaces 59, or via anin-band file download mechanism.

The method illustrated in the flowchart of FIG. 2 may be implemented byany stored instructions, such as software 22. When loaded into aprocessor, such as processor 39, software 22 would operate to verifyvideo formats supported by a particular display device. As indicatedabove, however, it will be appreciated that aspects of the presentinvention are not limited to any specific embodiments of computersoftware or signal processing methods.

Although a specific architecture has been described herein, includingspecific functional elements and relationships, it is contemplated thatthe systems and methods herein may be implemented in a variety of ways.For example, functional elements may be packaged together orindividually, or may be implemented by fewer, more or different devices,and may be either integrated within other products, or adapted to workwith other products externally. When one element is indicated as beingresponsive to another element, the elements may be directly orindirectly coupled.

It will furthermore be apparent that other and further forms of theinvention, and embodiments other than the specific embodiments describedabove, may be devised without departing from the spirit and scope of theappended claims and their equivalents, and it is therefore intended thatthe scope of this invention will only be governed by the followingclaims and their equivalents.

1. A method (200) for verifying a video format supported by a displaydevice (25), the display device (25) adapted to receive a digitaltelevision signal from a digital video source (10) via a digital videointerface (15), the method comprising: receiving (202) a data structure(75) provided by the display device (25), the data structure (75)specifying a plurality of timing parameters associated with a supportedvideo format; providing (204) a plurality of predetermined value ranges,each of the plurality of predetermined value ranges corresponding to oneof the plurality of timing parameters; separating (206) the receiveddata structure (75) into a plurality of portions, each of the pluralityof portions corresponding to one of the plurality of timing parameters;comparing (208) at least some of the plurality of portions with at leastsome of the plurality of predetermined value ranges; and based on thecomparisons, determining whether the supported video format is verified.2. A computer-readable medium (64, 70, 50, 71) encoded with a computerprogram which, when loaded into a processor (39, 77, 50, 71), implementsthe method of claim
 1. 3. The method according to claim 1, furthercomprising: based on whether the supported video format is verified,including the supported video format in a schedule of supported videoformats associated with the display device (25).
 4. The method accordingto claim 3, further comprising: when the supported video format is notverified, not including the supported video format on the schedule. 5.The method according to claim 3, further comprising: when the supportedvideo format is verified, including the supported video format on theschedule.
 6. The method according to claim 5, further comprising: basedon the comparisons, determining a picture aspect ratio of a verified,supported video format.
 7. The method according to claim 5, furthercomprising: presenting the schedule to a user of the display device forselection of a preferred video format.
 8. The method according to claim7, wherein the schedule is presented to the user as a menu adapted toenable the user to select the preferred video format from the menu. 9.The method according to claim 7, further comprising: based on aselection of the preferred video format by the user, transmitting thedigital television signal to the display device in the selected format,via the digital video interface (15).
 10. The method according to claim1, further comprising: storing the data structure in a memory (64). 11.The method according to claim 1, wherein the digital video interface(15) comprises a digital channel.
 12. The method according to claim 1,wherein the digital channel comprises an I²C bus.
 13. The methodaccording to claim 1, wherein the data structure (75) comprises VideoElectronics Standards Association Extended Display Identification Data.14. The method according to claim 1, wherein the display device (25)comprises one of a high definition television monitor; an extendeddefinition television monitor; and a standard definition televisionmonitor.
 15. The method according to claim 1, wherein the video formatcomprises one of: 1920×1080i; 1280×720p; 720×480p; and 720×480i.
 16. Themethod according to claim 1, wherein the receipt of the data structure(75) occurs upon hot plug connection of the display device to thedigital video source (10).
 17. The method according to claim 1, whereinthe plurality of portions include a predetermined number of bits. 18.The method according to claim 1, wherein the plurality of timingparameters comprise: horizontal active pixels, horizontal blankingpixels, vertical active lines, vertical blanking lines, horizontal syncoffset, horizontal sync pulse width, and vertical sync offset.
 19. Themethod according to claim 18, wherein the predetermined value rangescorrespond to actual timing parameters obtained by observation of adigital video source transmitting a digital television signal in thesupported video format over a digital video interface.
 20. An apparatusfor verifying a video format supported by a display device (25),comprising: a computer-readable storage medium (64); and a processor(39) responsive to the computer-readable storage medium (64) and to asoftware program (22), the software program (22), when loaded into theprocessor (39), operative to perform a method comprising: receiving adata structure (75) specifying a plurality of timing parametersassociated with a supported video format of the display device (25);accessing a plurality of predetermined value ranges, each of theplurality of predetermined value ranges corresponding to one of theplurality of timing parameters; separating the received data structure(75) into a plurality of portions, each of the plurality of portionscorresponding to one of the plurality of timing parameters; comparing atleast some of the plurality of portions with at least some of theplurality of predetermined value ranges; and based on the comparisons,determining whether the supported video format is verified.
 21. Theapparatus according to claim 20, wherein the processor is associatedwith the display device.
 22. The apparatus according to claim 20,wherein the processor is associated with a set-top box (10) adapted totransmit a video signal to the display device (25).
 23. The apparatusaccording to claim 20, wherein the processor is associated with adigital video interface (50/71) responsive to the display device (25).